Body dysmorphic disorder (BDD), also termed body dysmorphia or dysmorphic syndrome, but originally termed dysmorphophobia, is a mental disorder via obsessive preoccupation with a perceived defect in one's own appearance, viewed as so severe as to warrant exceptional measures to hide or fix it.[1] In BDD's delusional variant, the flaw is imagined.[2] If the flaw is actual, its importance is severely exaggerated.[2] BDD is categorized in the obsessive–compulsive spectrum.

Usually starting during adolescence, BDD is a fairly common mental disorder, affects men and women roughly equally, and may occur in some 1% to 2% of the population.[2] In fear of being thought vain, persons experiencing BDD tend to keep the preoccupation secret, and BDD is severely underdiagnosed.[2] Severely impairing quality of life, BDD can lead to social isolation and involves especially high rates of suicidal ideation.[2] The BDD subtype muscle dysmorphia, nearly exclusive to males, involves preoccupation that one's body or some part of it is too small.

As with most psychiatric diagnoses, BDD seems to have a causation that is biopsychosocial, an interaction of inherited, genetic, developmental, psychological, and social factors.[5] Although genetic factors appear to contribute,[5] and the personality trait introversion may contribute,[6] rates of childhood abuse and neglect are markedly elevated among persons experiencing BDD.[5][7] A heightened aesthetic sensitivity might also contribute.[5]

Whereas vanity concerns preoccupation with aggrandizing the appearance, BDD is compulsion to merely normalize the appearance.[2] While associating with perfectionism, BDD also reflects negative body image, [8] and shares features with obsessive-compulsive disorder (OCD),[9] but manifests greater levels of depression and social avoidance.[1] BDD has high comorbidity with social anxiety disorder.[10]

In BDD, the perceived bodily defect can be at virtually any area, yet is usually the nose, skin, or hair.[2] Attempts at self-treatment can paradoxically create lesions where none previously existed.[2] BDD often drives a quest to obtain dermatological treatment or cosmetic surgery, which interventions typically do not resolve the distress.[2] Sometimes deluded in believing that persons are covertly pointing out their flaws, some persons experiencing BDD can react violently to perceived putdowns.[2]

Most generally, one experiencing ruminates over the perceived bodily defect up to several hours daily, uses either social avoidance or camouflaging with cosmestics or apparel, repetitively checks the appearance, compares it to that of other persons, and might often seek verbal reassurances.[2][1] BDD's severity can wax and wane, and flareups tend to yield absences from school, work, or socializing, sometimes leading to protracted social isolation.[2] Severely impairing quality of life, BDD typically involves distress exceeding that of either major depressive disorder or type-2 diabetes, and rates of suicidal ideation and attempts are especially elevated.[2]

Estimates of prevalence and gender distribution have varied widely via discrepancies in diagnosis and reporting.[1] In American psychiatry, BDD gained diagnostic criteria in the DSM-IV, but clinicians' knowledge of it, especially among general practitioners, is constricted.[11] Meanwhile, the shame that persons feel about having the bodily concern, and fearing the stigma of vanity, hinders recognition.[2][12] BDD is sometimes mistaken for major depressive disorder or social phobia.[13] BDD is severely under-diagnosed even in psychiatric patients.[14] Correct diagnosis calls for specialized questioning and correlation with emotional distress or social dysfunction.[14] Estimates place the Body Dysmorphic Disorder Questionnaire's specificity at 92.5% and its sensitivity at 100%.[15]

Neuroimaging[19] suggest weaker connection between the amygdala (involved in basic emotions) and the orbitofrontal cortex (involved in regulation of emotional arousal).[20] (Cognitive-behavioral therapy may improve connections between the orbitofrontal cortex and the amygdala.[20])